JPH05339577A - Ferroelectric liquid crystal composition and liquid crystal display element - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in response speed, alignability and bistability by mixing a specified chiral compound with specified achiral compounds. CONSTITUTION:The title composition is prepared by mixing 3-40wt.% chiral compound of formula I (wherein A, B and C are each a bivalent aromatic hydrocarbon group, a bivalent alicyclic hydrocarbon group or a bivalent heterocyclic hydrocarbon group each of which may be substituted with halogen or cyano; X and Y are each -CH2O-, -OCH2- or the like; R<1> is alkyl or the like each of which may be substituted with halogen and in each of which one or more nonadjacent methylene groups may be replaced by O, S or CO; R<2> is alkyl or the like each of which may be substituted; n, p and q are each 0 or 1, q is 0 when n=0; m is 3-22; and C* is an asymmetric carbon atom) with at least 2wt.% achiral compound of formula II (wherein R<3> is meth) or ethyl; k is 3-16; and j is 4-16) and at least 2wt.% achiral compound of formula III (wherein D is 1,4-phenylene or the like each of which may be substituted with 1-2 fluorine atoms; E is 2,5-pyridinylene; and R<4> and R<5> are each 1-20C linear or branched alkyl which may be substituted with at least one fluorine atom).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferroelectric liquid crystal composition suitable for large-area, high-density, high-speed display, and particularly for use in a ferroelectric liquid crystal display element having a fast response speed. The present invention relates to a dielectric liquid crystal composition.

[0002]

2. Description of the Related Art A twisted nematic (TN) type is a typical one which has been widely put into practical use as a display system for liquid crystal display devices. The TN type uses a nematic liquid crystal phase and has problems such as a slow response speed and poor viewing angle characteristics when used for a display, as compared with a display system such as a CRT (Cathode Ray Tube).
Therefore, the display has been limited to a limited number of uses.

Recently, surface-stabilized ferroelectric liquid crystal devices have been developed by Clark, Lagerwall, and JP-A-56-.
107216, U.S. Pat. No. 4,367,924, etc.). In this device, a ferroelectric liquid crystal sandwiched by a substrate with a gap of about 2 μm combined with a polarizing plate controls the amount of transmitted light by changing the orientation of the molecular long axis according to the polarity of the applied electric field. It is characterized by high-speed response and bistability.
Moreover, since it is also excellent in viewing angle characteristics, this element is expected to be widely used as a large-capacity and high-density display element.

The ferroelectric liquid crystal has a chiral smectic C (hereinafter abbreviated as Sc ^* ) phase as one of the liquid crystal phases. Wide range of Sc ^* phase (expandable temperature range) to use ferroelectric liquid crystal as display device
It is required to have many properties such as having a high speed, responding at a high speed, exhibiting a good orientation for obtaining a good contrast during display, and having a good bistability.
Among the characteristics required for the above display device, it has been attempted to improve a wide range of Sc ^* phase by a method of mixing a liquid crystal compound. As a method for preparing such a composition, for example, smectic C which does not exhibit ferroelectricity is used. A method of adding an optically active compound to a liquid crystal compound or a liquid crystal mixture (hereinafter referred to as a base liquid crystal) exhibiting a phase (hereinafter abbreviated as Sc) is known (Mol. Cryst. Liq. Cryst., 89, 327 ( 1982)).
Here, as the components of the base liquid crystal exhibiting the Sc phase, phenylbenzoate-based, Schiff base-based, biphenyl-based,
Liquid crystal compounds such as phenylpyrimidine-based and phenylpyridine-based are used.

The improvement of the response speed has been attempted mainly by developing a liquid crystal compound or mixing a liquid crystal in consideration of high spontaneous polarization and low viscosity of the liquid crystal material. That is, the response of an element using ferroelectric liquid crystal (which is called surface-stabilized ferroelectric liquid crystal because the long axis of the liquid crystal molecule is strongly parallel to the substrate interface) is spontaneous with dielectric anisotropy. The polarization (P _S ) is characterized by direct interaction with the electric field (E), and the response time (τ) is generally given by the following equation: τ∝η / P _S E. η is the average viscosity coefficient of the liquid crystal. From the above equation, the response time becomes faster as the spontaneous polarization and the electric field become larger and the viscosity coefficient becomes smaller.

For example, when the structure of the ferroelectric liquid crystal compound is changed to increase the spontaneous polarization, the viscosity increases with the increase of the spontaneous polarization, and the response speed does not increase so much. Further, it is difficult to significantly reduce the viscosity because it is necessary to change the molecular structure while maintaining the spontaneous polarization. Chiral compounds having a fluorine atom-substituted alkyl chain have been proposed in JP-A-63-2024 and JP-A-1-246269 as ferroelectric liquid crystal compounds that have realized low viscosity while maintaining spontaneous polarization. There is. However, even if this compound is used alone or as a component of the composition to prepare a ferroelectric liquid crystal composition, sufficient high-speed response cannot be obtained.

Further, regarding the high-speed response by mixing liquid crystals, for example, 5-alkyl-2- (4-alkoxyphenyl) pyrimidine having a bicyclic structure which is a non-chiral phenylpyrimidine liquid crystal and 5-alkyl having a tricyclic structure are used. -2-
(4′-alkoxybiphenyl-4) pyrimidine and 5
-Alkoxy-2- (4'-alkylbiphenyl-4)
Pyrimidine (JP-A-61-291679, JP-A-2-265986) and bialkoxy 5-alkoxy-
2- (4-alkylphenyl) pyrimidine (JP-A-62-62
No. 137883, Japanese Unexamined Patent Publication No. 63-301872, Japanese Unexamined Patent Publication No. 2-173089) have been proposed as a liquid crystal display element. Ferroelectric liquid crystals obtained by mixing these with a chiral compound are good in terms of response speed, but have a problem that the orientation is not good or the bistability is not sufficient. ..
That is, when a liquid crystal having such a poor orientation or bistability is incorporated into the device, the display contrast is not sufficiently excellent. Further, when a biphenylpyrimidine-based non-chiral compound having a tricyclic structure is used, relatively good orientation can be obtained, but there is a problem that a large response speed cannot be obtained.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have a high-speed response and a wide Sc ^* phase (expanding a practical temperature range), and also have good properties in orientation and bistability. In order to obtain a liquid crystal display device, earnest studies have been conducted on a ferroelectric liquid crystal composition used therein. As a result, a relatively low viscosity and a chiral compound represented by the following general formula showing a high speed response (I), the following formula having a broad S _C phase compared with the conventional phenyl millimeter thymidine compound (II) Compared with the non-chiral compound represented and the non-chiral compound of the bicyclic pyrimidine type having a tricyclic structure which is said to be capable of imparting good orientation, the nematic phase and the smectic C phase are more stable and the viscosity is higher. Even when using a lower non-chiral compound represented by the following general formula (III), while maintaining good orientation,
It was found that a ferroelectric liquid crystal composition having a high-speed response, good bistability, and excellent driving characteristics in a wider temperature range can be obtained. Therefore, it is an object of the present invention to provide a ferroelectric liquid crystal composition which is excellent in high-speed response and has good properties in alignment and bistability, and which is particularly useful as a liquid crystal composition for liquid crystal display devices. And

[0009]

The above-mentioned object is a liquid crystal composition comprising a chiral compound and a non-chiral compound, wherein the chiral compound has the following general formula (I):

[0010]

[Chemical 4] [However, A, B and C are each independently a divalent aromatic hydrocarbon group, a divalent alicyclic hydrocarbon group or a divalent heterocyclic ring which may be substituted with a halogen atom or a cyano group. represents a group, X and Y are each independently, -CH ₂ O-,
_{-OCH 2 -, - COO -,} - OCO -, - CH = CH
Represents a — or —C≡C—, R ¹ represents a linear or branched alkyl group or an alkoxy group which may be substituted with a halogen atom (provided that at least one methylene group which is not adjacent is O, S or CO may be substituted), R ²
Represents an optionally substituted alkyl group or alkenyl group, n, p and q each independently represent 0 or 1 (provided that q = 0 when n = 0), and m represents 3 to 3. 11
Represents an integer, and * represents an asymmetric carbon atom. ] The non-chiral compound represented by the following general formula (II):

[0011]

[Chemical 5] [However, R ³ represents a methyl group or an ethyl group, and k
Represents an integer in the range of 3 to 16, and j is 4 to
Represents an integer in the range of 16] and the following general formula (III):

[0012]

[Chemical 6] [Wherein D is 1,4-phenylene group or 1,4-phenylene group which may be substituted with one or two fluorine atoms or cyano group]
Represents a cyclohexylene group, E represents a 2,5-pyridinylene group, and R ⁴ and R ⁵ are each independently a straight chain having 1 to 20 carbon atoms which may be substituted with one or more fluorine atoms. Or represents a branched alkyl group (however,
One or more of the non-adjacent methylene groups may be replaced by O, S or CO). ] It can be achieved by a ferroelectric liquid crystal composition characterized by containing a non-chiral compound represented by the following.

Further, the above-mentioned object is to dispose two substrates having at least a transparent electrode and an alignment film in this order so that the alignment films face each other, and liquid crystal is sealed in a space between the alignment films. in the liquid crystal display device comprising Te, the liquid crystal is above ferroelectric liquid crystal composition, the alignment film, and a pretilt angle at S _a phase of the ferroelectric liquid crystal composition 5 degrees or more, at least one It can also be achieved by a liquid crystal display element characterized in that an insulating layer having a relative dielectric constant of 5 or more is provided between the transparent electrode of the substrate and the alignment film.

A preferred embodiment of the present invention is as follows. 1) The ferroelectric liquid crystal composition, wherein the chiral compound represented by the general formula (I) is contained in the ferroelectric liquid crystal composition in a range of 3 to 40% by weight. And a liquid crystal display device.

2) The non-chiral compound represented by the above general formula (II) is contained in the ferroelectric liquid crystal composition in an amount of 3 to 30% by weight. Liquid crystal composition and liquid crystal display device.

3) The ferroelectric liquid crystal composition containing the non-chiral compound represented by the general formula (III) in an amount of 3 to 30% by weight. Liquid crystal composition and liquid crystal display device.

4) The sum of the chiral compound represented by the general formula (I), the non-chiral compound represented by the general formula (II) and the non-chiral compound represented by the general formula (III) is
The ferroelectric liquid crystal composition and the liquid crystal display device, characterized in that they account for 12% by weight or more in the liquid crystal composition.

5) A combination of the chiral compound represented by the general formula (I), the non-chiral compound represented by the general formula (II) and the non-chiral compound represented by the general formula (III). The ferroelectric liquid crystal composition and the liquid crystal display device, wherein the ratio is in the range of 20:80 to 80:20 (general formula (I): general formulas (II) and (III)).

[Detailed Description of the Invention] First, the chiral compound (I) represented by the above general formula (I) will be described. In the general formula (I), A, B and C are each independently a divalent aromatic hydrocarbon group which may be substituted with a halogen atom or a cyano group, a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. Represents a valent heterocyclic group. The halogen atom is preferably a fluorine atom or the like. When A, B and C have a substituent, the number of substituents is preferably 1-6. As the divalent aromatic hydrocarbon group, for example, 1,4-phenylene group and 2,6-naphthylene group are preferable, and as the divalent alicyclic hydrocarbon group, for example, 1,4-cyclohexylene group is preferable. Further, the divalent heterocyclic group is preferably a heterocyclic group containing one or more nitrogen atoms in addition to carbon atoms (preferably a 6-membered ring), for example, 2,
5-pyrimidinylene group, 2,5-pyridinylene group, 3,
6-pyridinylene group, 2,5-pyrazinylene group, 3,6
-Pyridazinylene group, 3,6-tetrazinylene group, 1,
2,4-triazine-3,6-ylene group and the like can be mentioned as preferable examples.

R ¹ represents a linear or branched alkyl group or alkoxy group which may be substituted with a halogen atom, and preferably has no substituent or has 1 to 4 halogen atoms (preferably fluorine). Atom) is a linear or branched alkyl group or alkoxy group having 1 to 20 carbon atoms. Further, at least one of methylene groups not adjacent to the alkyl group or alkoxy group represented by R ¹ is
It may be substituted with O, S or CO. Preferred examples of the group represented by R ¹ include pentyl, hexyl,
Heptyl, octyl, nonyl, decyl, dodecyl, undecyl, 7-methoxyheptyl, 8-methoxyoctyl, 10-methoxydecyl, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, dodecyloxy, undecyloxy, 7-methoxyheptyloxy, 8-methoxyoctyloxy, 10-methoxydecyloxy, 7-methyloctyl, 8-methylnonyl, 9-methyldecyl, 7-ethylnonyl, 7-methyloctyloxy, 8-methylnonyloxy, octylthio, nonylthio , 7-methyloctylthio and nonanoyl. Further, R ¹ is represented by the following formula (I-1):

[0021]

[Chemical 7]

(Wherein R ⁷ represents an optionally substituted alkyl group or alkenyl group, m 1 represents an integer of 3 to 11, and * represents an asymmetric carbon atom). It may be.

R ² represents an optionally substituted alkyl group or alkenyl group, and is preferably an unsubstituted or substituted halogen atom (preferably fluorine atom) or the like having 1 to 4 carbon atoms. Or 2 to 4 carbon atoms
Represents an alkenyl group. Particularly preferred groups represented by R ² are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, vinyl, allyl, trifluoromethyl, 2,2,2.
-Trifluoroethyl and the like. Further, p and q are preferably 0.

The above chiral compound (I) can be synthesized by the synthetic route shown in the following reaction formula (A).

[0025]

[Chemical 8]

[In the reaction formula (A), A, B, C,
X, Y, R ¹ , R ² , n, p, q and m are the same as defined in the general formula (I)].

That is, optically active epichlorohydrin (1)
Is reacted with an alkoxyalkyl magnesium bromide (2) in the presence of copper iodide to synthesize an optically active compound (3), and the optically active compound (3) is dehydrated with a base to give an optically active epoxy compound (4). ) Is synthesized, and the optically active epoxy compound (4) is reacted with hydrogen fluoride pyridine to synthesize the optically active fluoroalcohol compound (5).
Compound (5) was converted into p-toluenesulfonic acid chloride (Ts
Cl) to synthesize the tosylate compound (6), and then the compound (6) is reacted with the compound (7) to synthesize the chiral compound (I). When synthesizing a chiral compound in which R ² and R ⁷ are the same and m and m1 are the same, HO-A- (X) _p -B- is used instead of the compound (7).
A diol compound represented by (Y) _q- (C) _n- OH may be used.

Examples of the compound (5) that can be used in the above reaction include the following compounds.

2-fluoro-5-methoxy-1-pentanol 2-fluoro-5-ethoxy-1-pentanol 2-fluoro-5-vinyloxy-1-pentanol 2-fluoro-5-allyloxy-1-pen Tanol 2-fluoro-5-propyloxy-1-pentanol 2-fluoro-5- (1-methylethyloxy) -1-
Pentanol 2-fluoro-5-n-butyloxy-1-pentanol 2-fluoro-5- (2-methylpropyloxy) -1
-Pentanol 2-fluoro-5- (1-methylpropyloxy) -1
-Pentanol 2-fluoro-5- (1,1-dimethylethyloxy)
-1-Pentanol 2-fluoro-5- (trifluoromethyloxy) -1
-Pentanol 2-fluoro-5- (2,2,2-trifluoroethyloxy) -1-pentanol

2-Fluoro-6-methoxy-1-hexanol 2-fluoro-6-ethoxy-1-hexanol 2-fluoro-6-vinyloxy-1-hexanol 2-fluoro-6-allyloxy-1-hexanol 2-fluoro -6-Propyloxy-1-hexanol 2-fluoro-6- (1-methylethyloxy) -1-
Hexanol 2-fluoro-6-n-butyloxy-1-hexanol 2-fluoro-6- (2-methylpropyloxy) -1
-Hexanol 2-fluoro-6- (1-methylpropyloxy) -1
-Hexanol 2-fluoro-6- (1,1-dimethylethyloxy)
-1-hexanol 2-fluoro-6- (trifluoromethyloxy) -1
-Hexanol 2-fluoro-6- (2,2,2-trifluoroethyloxy) -1-hexanol

2-fluoro-7-methoxy-1-heptanol 2-fluoro-7-ethoxy-1-heptanol 2-fluoro-7-vinyloxy-1-heptanol 2-fluoro-7-allyloxy-1-heptanol 2-fluoro -7-Propyloxy-1-heptanol 2-fluoro-7- (1-methylethyloxy) -1-
Heptanol 2-fluoro-7-n-butyloxy-1-heptanol 2-fluoro-7- (2-methylpropyloxy) -1
-Heptanol 2-fluoro-7- (1-methylpropyloxy) -1
-Heptanol 2-fluoro-7- (1,1-dimethylethyloxy)
-1-Heptanol 2-fluoro-7- (trifluoromethyloxy) -1
-Heptanol 2-fluoro-7- (2,2,2-trifluoroethyloxy) -1-heptanol

2-fluoro-8-methoxy-1-octanol 2-fluoro-8-ethoxy-1-octanol 2-fluoro-8-vinyloxy-1-octanol 2-fluoro-8-allyloxy-1-octanol 2-fluoro -8-Propyloxy-1-octanol 2-fluoro-8- (1-methylethyloxy) -1-
Octanol 2-fluoro-8-n-butyloxy-1-octanol 2-fluoro-8- (2-methylpropyloxy) -1
-Octanol 2-fluoro-8- (1-methylpropyloxy) -1
-Octanol 2-fluoro-8- (1,1-dimethylethyloxy)
-1-Octanol 2-fluoro-8- (trifluoromethyloxy) -1
-Octanol 2-fluoro-8- (2,2,2-trifluoroethyloxy) -1-octanol

2-Fluoro-9-methoxy-1-nonanol 2-Fluoro-9-ethoxy-1-nonanol 2-Fluoro-9-vinyloxy-1-nonanol 2-Fluoro-9-allyloxy-1-nonanol 2-fluoro -9-Propyloxy-1-nonanol 2-fluoro-9- (1-methylethyloxy) -1-
Nonanol 2-fluoro-9-n-butyloxy-1-nonanol 2-fluoro-9- (2-methylpropyloxy) -1
-Nonanol 2-fluoro-9- (1-methylpropyloxy) -1
-Nonanol 2-fluoro-9- (1,1-dimethylethyloxy)
-1-nonanol 2-fluoro-9- (trifluoromethyloxy) -1
-Nonanol 2-fluoro-9- (2,2,2-trifluoroethyloxy) -1-nonanol

2-fluoro-10-methoxy-1-decanol 2-fluoro-10-ethoxy-1-decanol 2-fluoro-10-vinyloxy-1-decanol 2-fluoro-10-allyloxy-1-decanol 2-fluoro -10-Propyloxy-1-decanol 2-fluoro-10- (1-methylethyloxy) -1
-Decanol 2-fluoro-10-n-butyloxy-1-decanol 2-fluoro-10- (2-methylpropyloxy)-
1-decanol 2-fluoro-10- (1-methylpropyloxy)-
1-decanol 2-fluoro-10- (1,1-dimethylethyloxy) -1-decanol 2-fluoro-10- (trifluoromethyloxy)-
1-decanol 2-fluoro-10- (2,2,2-trifluoroethyloxy) -1-decanol

2-fluoro-11-methoxy-1-undecanol 2-fluoro-11-ethoxy-1-undecanol 2-fluoro-11-vinyloxy-1-undecanol 2-fluoro-11-allyloxy-1-undecanol 2-fluoro -11-Propyloxy-1-undecanol 2-fluoro-11- (1-methylethyloxy) -1
-Undecanol 2-fluoro-11-n-butyloxy-1-undecanol 2-fluoro-11- (2-methylpropyloxy)-
1-Undecanol 2-fluoro-11- (1-methylpropyloxy)-
1-Undecanol 2-fluoro-11- (1,1-dimethylethyloxy) -1-undecanol 2-fluoro-11- (trifluoromethyloxy)-
1-Undecanol 2-fluoro-11- (2,2,2-trifluoroethyloxy) -1-undecanol

2-fluoro-12-methoxy-1-dodecanol 2-fluoro-12-ethoxy-1-dodecanol 2-fluoro-12-vinyloxy-1-dodecanol 2-fluoro-12-allyloxy-1-dodecanol 2-fluoro -12-Propyloxy-1-dodecanol 2-Fluoro-12- (1-methylethyloxy) -1
-Dodecanol 2-fluoro-12-n-butyloxy-1-dodecanol 2-fluoro-12- (2-methylpropyloxy)-
1-dodecanol 2-fluoro-12- (1-methylpropyloxy)-
1-dodecanol 2-fluoro-12- (1,1-dimethylethyloxy) -1-dodecanol 2-fluoro-12- (trifluoromethyloxy)-
1-dodecanol 2-fluoro-12- (2,2,2-trifluoroethyloxy) -1-dodecanol

The following compounds can be mentioned as specific examples of the chiral compound (1).

[0038]

[Chemical 9]

[0039]

[Chemical 10]

[0040]

[Chemical 11]

[0041]

[Chemical formula 12]

[0042]

[Chemical 13]

[0043]

[Chemical 14]

[0044]

[Chemical 15]

[0045]

[Chemical 16]

[0046]

[Chemical 17]

[0047]

[Chemical 18]

[0048]

[Chemical 19]

[0049]

[Chemical 20]

[0050]

[Chemical 21]

[0051]

[Chemical formula 22]

[0052]

[Chemical formula 23]

[0053]

[Chemical formula 24]

[0054]

[Chemical 25]

[0055]

[Chemical formula 26]

[0056]

[Chemical 27]

[0057]

[Chemical 28]

[0058]

[Chemical 29]

[0059]

[Chemical 30]

[0060]

[Chemical 31]

[0061]

[Chemical 32]

[0062]

[Chemical 33]

[0063]

[Chemical 34]

[0064]

[Chemical 35]

[0065]

[Chemical 36]

[0066]

[Chemical 37]

[0067]

[Chemical 38]

[0068]

[Chemical Formula 39]

[0069]

[Chemical 40]

[0070]

[Chemical 41]

[0071]

[Chemical 42]

[0072]

[Chemical 43]

[0073]

[Chemical 44]

[0074]

[Chemical 45]

[0075]

[Chemical 46]

[0076]

[Chemical 47]

[0077]

[Chemical 48]

A synthesis example of the chiral compound (I) (synthesis of the above exemplified compound A22) will be shown. (S) -2-Fluoro-7
-Methoxyheptyl silate 490 mg, 4- [2-
570 mg of potassium carbonate was added to 571 mg of (4-heptylphenyl) -5-pyrimidinyl] phenol and 3 ml of DMF, and the mixture was stirred at 110 ° C. for 8 hours. After completion of the reaction, add 5 ml of water, extract with ethyl acetate, wash with water,
After dehydration, the solvent was distilled off. The crude product was purified by column chromatography using a mixed solvent of hexane / ethyl acetate (8/1), recrystallized from ethanol, and 445 mg of 2-fluoro-8-methoxy-1-.
[4- [2- (4-heptylphenyl) -5-pyrimidyl] phenyloxy] heptane (the above exemplified compound 22)
Number). The phase transition temperature is shown below. _{79.1 ℃. 90 ℃ 94 ℃ 115} ℃ 147 ℃ 172 ℃ Cryst. → S 5 → S 4 → S 3 → Sc * → S A → Iso 57.3 ℃. 90 ℃ 94 ℃ 115 ℃ 147 ℃ 172 ℃ S 6 ← S 5 ← S ₄ ← S ₃ ← Sc ^* ← S _A ← Iso

The non-chiral compound of the present invention represented by the above general formula (II) will be described. R ³ represents a methyl group or an ethyl group. k represents an integer in the range of 3 to 16. And, k is preferably an integer in the range of 4 to 14, and particularly preferably an integer in the range of 4 to 12. j represents an integer in the range of 4 to 16. Then, j is preferably an integer in the range of 4 to 14, and particularly preferably an integer in the range of 4 to 12. R
³ is preferably a methyl group. When R ³ is an ethyl group, j is particularly preferably in the range of 8-14.

The compound represented by the above general formula (II) can be produced, for example, according to the route diagram of the following reaction formula.

[0081]

[Chemical 49] In the above reaction formula, R ⁸ represents a linear alkyl group, R ⁶ is an alkyl group such as a methyl group or an ethyl group, X is a halogen atom, p-toluenesulfonyloxy group, benzenesulfonyloxy group, methanesulfonyl group, etc. And R ⁹ represents an alkyl group in which the terminal carbon atom is substituted with two methyl groups or ethyl groups. In the above formula, p-alkylbenzamidine hydrochloride (1) is reacted with methoxymalonic acid diester in the presence of sodium alcoholate to give a diol (2), which is halogen-substituted with a halogenating agent such as phosphorus oxychloride. (3), dehalogenation in the presence of a base to give (4), which is heat treated in diethylene glycol in the presence of an alkali to give (5), which is then etherified to give a compound of the general formula (II) The compound can be obtained.

The non-chiral compound represented by the above general formula (II) can also be synthesized according to another synthetic method described in JP-A No. 1-167893.

Examples of the non-chiral compound represented by the above general formula (II) include the following compounds.

[0084]

[Chemical 50]

[0085]

[Chemical 51]

[0086]

[Chemical 52]

[0087]

[Chemical 53]

[0088]

[Chemical 54]

[0089]

[Chemical 55]

[0090]

[Chemical 56]

[0091]

[Chemical 57]

[0092]

[Chemical 58]

[0093]

[Chemical 59]

[0094]

[Chemical 60]

[0095]

[Chemical formula 61]

Next, the non-chiral compound of the present invention represented by the above general formula (III) will be described. D may be substituted with one or two fluorine atoms or a cyano group 1,
It represents a 4-phenylene group or a 1,4-cyclohexylene group, and E represents a 2,5-pyridinylene group. The 2,5-pyridinylene group is preferably bonded to the pyrimidine ring at the 5-position as in the following general formula (IV).

[0097]

[Chemical formula 62] [However, D, R ⁴ and R ⁵ mean the same as defined in the above general formula (III)]

R ⁴ and R ⁵ each independently have 1 to 2 carbon atoms which may be substituted with one or more fluorine atoms.
0 represents a linear or branched alkyl group. However, one or more non-adjacent methylene groups may be replaced by O, S or CO. Each of R ⁴ and R ⁵ is preferably an unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms. Preferable examples of R ⁴ and R ⁵ include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group and decyl group, 5-methyl group. Mention may be made of hexyl groups and branched alkyl groups such as 6-methylheptyl and 7-methyloctyl groups.

The compound of the general formula (III) can be prepared as shown in the following figure.
For example, the desired compound of (III) can be produced by reacting amidine hydrochloride derived from 2-substituted-5-cyanopyridine with the corresponding acrolein. In addition, by reacting with a corresponding substituted malonic acid diester instead of acrolein, 2-pyridinyl-5-substituted-4,
The compound of (III) can also be produced by a method via a 6-dihydroxypyrimidine derivative.

[0100]

[Chemical 63]

The method for synthesizing the above-mentioned 2-substituted-5-cyanopyridine is described in detail in JP-A-61-246167, and the method for closing the pyrimidine ring is JP-A-60-543271. Publication, JP-A-6
It is described in detail in Japanese Patent Laid-Open No. 3-301872 and the like. Examples of the compound represented by the general formula (III) include the compounds shown below.

2- (4-propylphenyl) -5- (5
-Pentyl-2-pyrimidinyl) -pyridine 2- (4-propylphenyl) -5- (5-hexyl-
2-Pyrimidinyl) -pyridine 2- (4-butylphenyl) -5- (5-pentyl-2)
-Pyrimidinyl) -pyridine 2- (4-butylphenyl) -5- (5-hexyl-2)
-Pyrimidinyl) -pyridine 2- (4-pentylphenyl) -5- (5-pentyl-
2-Pyrimidinyl) -pyridine 2- (4-pentylphenyl) -5- (5-hexyl-
2-pyrimidinyl) -pyridine 2- (4-pentylphenyl) -5- (5-heptyl-
2-pyrimidinyl) -pyridine 2- (4-pentylphenyl) -5- (5-octyl-
2-pyrimidinyl) -pyridine

2- (4-pentylphenyl) -5- (5
-Nonyl-2-pyrimidinyl) -pyridine 2- (4-hexylphenyl) -5- (5-hexyl-
2-pyrimidinyl) -pyridine 2- (4-hexylphenyl) -5- (5-heptyl-
2-pyrimidinyl) -pyridine 2- (4-hexylphenyl) -5- (5-octyl-
2-pyrimidinyl) -pyridine 2- (4-hexylphenyl) -5- (5-nonyl-2
-Pyrimidinyl) -pyridine 2- (4-heptylphenyl) -5- (5-pentyl-
2-pyrimidinyl) -pyridine 2- (4-heptylphenyl) -5- (5-hexyl-
2-pyrimidinyl) -pyridine 2- (4-heptylphenyl) -5- (5-heptyl-
2-pyrimidinyl) -pyridine 2- (4-heptylphenyl) -5- (5-octyl-
2-pyrimidinyl) -pyridine

2- (4-heptylphenyl) -5- (5
-Nonyl-2-pyrimidinyl) -pyridine 2- (4-octylphenyl) -5- (5-heptyl-
2-pyrimidinyl) -pyridine 2- (4-octylphenyl) -5- (5-octyl-
2-pyrimidinyl) -pyridine 2- (4-octylphenyl) -5- (5-nonyl-2)
-Pyrimidinyl) -pyridine 2- (4-octylphenyl) -5- (5-decyl-2)
-Pyrimidinyl) -pyridine 2- (4-nonylphenyl) -5- (5-octyl-2)
-Pyrimidinyl) -pyridine 2- (4-nonylphenyl) -5- (5-nonyl-2-
Pyrimidinyl) -pyridine 2- (4-nonylphenyl) -5- (5-decyl-2-
Pyrimidinyl) -pyridine 2- (4-decylphenyl) -5- (5-decyl-2-
Pyrimidinyl) -pyridine

2- (4-pentylphenyl) -5- [5
-(5-Methylhexyl) -2-pyrimidinyl] -pyridine 2- (4-hexylphenyl) -5- [5- (6-methylheptyl) -2-pyrimidinyl] -pyridine 2- (4-heptylphenyl)- 5- [5- (7-Methyloctyl) -2-pyrimidinyl] -pyridine 2- [4- (2-methylpropyl) phenyl] -5-
(5-Pentyl-2-pyrimidinyl) -pyridine 2- [4- (3-methylbutyl) phenyl] -5- (5
-Hexyl-2-pyrimidinyl) -pyridine 2- [4- (4-methylpentyl) phenyl] -5-
(5-heptyl-2-pyrimidinyl) -pyridine 2- [4- (5-methylhexyl) phenyl] -5-
(5-Octyl-2-pyrimidinyl) -pyridine 2- [4- (6-methylheptyl) phenyl] -5-
(5-Octyl-2-pyrimidinyl) -pyridine 2- [4- (6-methylheptyl) phenyl] -5-
[5- (7-Methyloctyl) -2-pyrimidinyl]-
Pyridine

2- (3-Fluoro-4-pentylphenyl) -5- (5-hexyl-2-pyrimidinyl) -pyridine 2- (3-Fluoro-4-pentylphenyl) -5-
(5-heptyl-2-pyrimidinyl) -pyridine

2- (2,3-difluoro-4-hexylphenyl) -5- (5-heptyl-2-pyrimidinyl)
-Pyridine 2- (2-cyano-4-hexylphenyl) -5- (5
-Octyl-2-pyrimidinyl) -pyridine 2- (3-cyano-4-heptylphenyl) -5- (5
-Heptyl-2-pyrimidinyl) -pyridine 2- (2,3-dicyano-4-heptylphenyl) -5
-(5-octyl-2-pyrimidinyl) -pyridine

2- (4-pentyloxyphenyl) -5
-(5-Pentyl-2-pyrimidinyl) -pyridine 2- (4-pentyloxyphenyl) -5- (5-hexyl-2-pyrimidinyl) -pyridine 2- (4-hexyloxyphenyl) -5- (5- Heptyl-2-pyrimidinyl) -pyridine 2- (4-heptyloxyphenyl) -5- (5-octyl-2-pyrimidinyl) -pyridine 2- (4-hexylphenyl) -5- (5-heptyloxy-2- Pyrimidinyl) -pyridine 2- (4-hexylphenyl) -5- (5-octyloxy-2-pyrimidinyl) -pyridine 2- (4-heptylphenyl) -5- (5-heptyloxy-2-pyrimidinyl) -pyridine 2- (4-heptylphenyl) -5- (5-octyloxy-2-pyrimidinyl) -pyridine 2- (4-butylphenyl) 5- (5-methoxy-pentyl-2-pyrimidinyl) - pyridine

2- (4-heptylphenyl) -5- (5
-Methoxypentyloxy-2-pyrimidinyl) -pyridine 2- (4-methoxyphenyl) -5- (5-heptyl-
2-Pyrimidinyl) -pyridine 2- (4-heptylthiophenyl) -5- (5-heptyl-2-pyrimidinyl) -pyridine 2- (4-heptylphenyl) -5- (5-octylthio-2-pyrimidinyl)- Pyridine

2- (trans-4-propylcyclohexyl) -5- (5-pentyl-2-pyrimidinyl) -pyridine 2- (trans-4-propylcyclohexyl) -5-
(5-hexyl-2-pyrimidinyl) -pyridine 2- (trans-4-propylcyclohexyl) -5-
(5-heptyl-2-pyrimidinyl) -pyridine 2- (trans-4-propylcyclohexyl) -5-
(5-octyl-2-pyrimidinyl) -pyridine 2- (trans-4-butylcyclohexyl) -5-
(5-Pentyl-2-pyrimidinyl) -pyridine 2- (trans-4-butylcyclohexyl) -5-
(5-hexyl-2-pyrimidinyl) -pyridine 2- (trans-4-butylcyclohexyl) -5-
(5-heptyl-2-pyrimidinyl) -pyridine 2- (trans-4-butylcyclohexyl) -5-
(5-octyl-2-pyrimidinyl) -pyridine

2- (trans-4-pentylcyclohexyl) -5- (5-pentyl-2-pyrimidinyl) -pyridine 2- (trans-4-pentylcyclohexyl) -5-
(5-hexyl-2-pyrimidinyl) -pyridine 2- (trans-4-pentylcyclohexyl) -5-
(5-heptyl-2-pyrimidinyl) -pyridine 2- (trans-4-pentylcyclohexyl) -5-
(5-Octyl-2-pyrimidinyl) -pyridine 2- (trans-4-pentylcyclohexyl) -5-
(5-nonyl-2-pyrimidinyl) -pyridine 2- (trans-4-pentylcyclohexyl) -5-
(5-decyl-2-pyrimidinyl) -pyridine

2- (trans-4-hexylcyclohexyl) -5- (5-heptyl-2-pyrimidinyl) -pyridine 2- (trans-4-hexylcyclohexyl) -5-
(5-Octyl-2-pyrimidinyl) -pyridine 2- (trans-4-heptylcyclohexyl) -5-
(5-heptyl-2-pyrimidinyl) -pyridine 2- (trans-4-heptylcyclohexyl) -5-
(5-octyl-2-pyrimidinyl) -pyridine 2- (trans-4-octylcyclohexyl) -5-
(5-octyl-2-pyrimidinyl) -pyridine 2- (trans-4-octylcyclohexyl) -5-
(5-nonyl-2-pyrimidinyl) -pyridine 2- (trans-4-propylcyclohexyl) -5-
(5-pentyloxyheptyl-2-pyrimidinyl)-
Pyridine 2- (trans-4-butylcyclohexyl) -5-
(5-Hexyloxy-2-pyrimidinyl) -pyridine 2- (trans-4-pentylcyclohexyl) -5-
(5-heptyloxy-2-pyrimidinyl) -pyridine 2- (trans-4-hexylcyclohexyl) -5-
(5-Octyloxy-2-pyrimidinyl) -pyridine 2- (trans-4-heptylcyclohexyl) -5-
(5-octyloxy-2-pyrimidinyl) -pyridine

Specific synthetic examples of the compound of the general formula (III) are shown below.

[Synthesis Example 1] 2- (4-heptylphenyl) -5- (5-pentyl-
2-Pyrimidinyl) -pyridine Sodium methoxide 1.07 g (19.6 mmol) in a solution of methanol 30 ml, 2- (4-heptylphenyl) -5-pyridinyl amidine hydrochloride 2.0 g
(6.02 mmol) and α-pentyl-β-dimethylaminoacrolein (1.02 g, 6.02 mmol) were added, and the mixture was refluxed for 10 hours. The reaction mixture was poured into an aqueous acetic acid solution and extracted with ethyl acetate. The organic layer was washed with water and the solvent was evaporated. The residue was purified by column chromatography and recrystallized from ethanol to obtain 0.22 g of 2- (4-heptylphenyl) -5- (5-pentyl-2-pyrimidinyl) -pyridine. The obtained compound had a liquid crystal phase, and its phase transition temperature (° C) was as follows. 77.5 ℃ 113.9 ℃ 155.4 ℃ 179.7 ℃ Cr ← → S _C ← → S _A ← → N ← → I

[Synthesis Example 2] 2- (4-heptylphenyl) -5- (5-heptyl-
2-pyrimidinyl) -pyridine (Exemplified compound b06) Synthesis Example 1 except that α-pentyl-β-dimethylaminoacrolein was used instead of α-pentyl-β-dimethylaminoacrolein in Synthesis Example 1.
2- (4-heptylphenyl)-
5- (5-heptyl-2-pyrimidinyl) -pyridine was obtained. The obtained compound had a liquid crystal phase, and its phase transition temperature (° C) was as follows. 60.5 ℃ 144.4 ℃ 174.5 ℃ 178.2 ℃ Cr ← → S _C ← → S _A ← → N ← → I

[Synthesis Example 3] 2- (4-heptylphenyl) -5- [5- (7-methyloctyl) -2-pyrimidinyl] -pyridine In synthesis example 1, α-pentyl-β-dimethylaminoacrolein was used. Instead of using α- (7-methyloctyl) -β-dimethylaminoacrolein, 2- (4-heptylphenyl) -5- [5- (7 -Methyloctyl) -2
-Pyrimidinyl] -pyridine was obtained. The obtained compound had a liquid crystal phase, and its phase transition temperature (° C) was as follows. (57.0 ℃) 64.0 ℃ 97.0 ℃ 164.0 ℃ Cr (← → S G) ← → S F ← → S C ← → I

The ferroelectric liquid crystal composition of the present invention has the above general formula (I) having an asymmetric carbon atom bonded to a fluorine atom and an alkoxyalkyl group, which exhibits a relatively low viscosity and a high-speed response.
In chiral compounds represented further, by way of non-chiral compounds, achiral compounds represented by the general formula (II) having a broad S _C phase compared with the conventional phenyl millimeter thymidine-based compound and the conventional excellent orientation As compared with the bicyclic pyrimidine-based non-chiral compound having a tricyclic structure which is said to be impartable, the above general formula (III) having a more stable nematic phase and smectic C phase and a lower value in viscosity is also used. The main component is a non-chiral compound represented by (). When such a composition is incorporated into a liquid crystal cell to form an element, it exhibits not only a high-speed response but also good orientation, and is excellent in bistability. Liquid crystal display device can be obtained. Further, such characteristics can be obtained in a wide temperature range.

The chiral compound represented by the above general formula (I) is generally contained in the ferroelectric liquid crystal composition in an amount of 3% by weight or more, preferably 3 to 40% by weight, more preferably 5 to 30%.
A weight% range is preferred.

The non-chiral compound represented by the general formula (II) is generally contained in the composition in an amount of 2% by weight or more, preferably 3 to 30% by weight, more preferably 3 to 25% by weight. .. The non-chiral compound represented by the general formula (III) is generally contained in the composition in an amount of 2% by weight or more, preferably 3 to 30% by weight, and further 3 to 25% by weight.
Is preferred.

The total of the chiral compound represented by the general formula (I), the non-chiral compound represented by the general formula (II) and the non-chiral compound represented by the general formula (III) is the same in the liquid crystal composition. It is generally 12% by weight or more, preferably 15% by weight or more. Further, the chiral compound represented by the general formula (I), the non-chiral compound represented by the general formula (II), and the general formula
The ratio to the total of the non-chiral compound represented by (III) is 2
It is preferably in the range of 0:80 to 80:20 (general formula (I): general formulas (II) and (III)), and further 30:
It is preferably in the range of 70 to 70:30. Also,
It is preferable that the composition contains 40% by weight or more of a non-chiral compound.

The ferroelectric liquid crystal composition of the present invention may contain a chiral compound other than the chiral compound (I). Preferred examples of other chiral compounds include 5-octyl-2- [4-((2S) -2-fluorooctyloxy) phenyl] pyrimidine 5-[(2S) -2-((2S) -2-propyl. Oxypropanoyloxy) propyloxy] -2- (4-octyloxyphenyl) pyrimidine 5-[(2S) -2-((2S) -2-propyloxypropanoyloxy) propyloxy] -2- (4 ′ −
Heptylbiphenyl-4-yl) pyrimidine 5-((2S) -2-methylbutyl) -2- (4'-heptylbiphenyl-4-yl) pyrimidine and the like can be mentioned.

The ferroelectric liquid crystal composition of the present invention may contain other non-chiral compounds other than the non-chiral compounds represented by the general formulas (II) and (III). The following compounds can be mentioned as an example of a preferable non-chiral compound.

5-decyl-2- (4-octylphenyl) pyrimidine 5-undecyl-2- (4-octylphenyl) pyrimidine 5-dodecyl-2- (4-octylphenyl) pyrimidine 5-dodecyl-2- (4 -Nonylphenyl) pyrimidine

5-nonyl-2- [4- (8-methylnonyl) phenyl] pyrimidine 5-decyl-2- [4- (8-methylnonyl) phenyl] pyrimidine 5-decyl-2- [4- (9-methyldecyl) ) Phenyl] pyrimidine 5- (9-methyldecyl) -2- [4- (8-methylnonyl) phenyl] pyrimidine 5- (9-methyldecyl) -2- [4- (9-methyldecyl) phenyl] pyrimidine 5- (10 -Methylundecyl) -2- [4- (9-methyldecyl) phenyl] pyrimidine

5-nonyloxy-2- (4-heptylphenyl) pyrimidine 5-octyl-2- (4-octyloxyphenyl) pyrimidine 5-nonyl-2- (4-octyloxyphenyl) pyrimidine 5-heptyl-2- (4-nonyloxyphenyl) pyrimidine 5-hexyl-2- (4'-pentylbiphenyl-4-
Il) pyrimidine 5-heptyl-2- (4'-pentylbiphenyl-4-
Il) pyrimidine 5-octyl-2- (4'-heptylbiphenyl-4-
Il) pyrimidine

5-heptyl-2- (4-heptyloxyphenyl) pyridine 5-heptyl-2- (4-octyloxyphenyl) pyridine 5-heptyl-2- (4-nonyloxyphenyl) pyridine

1- (4-heptylcyclohexyl) -4
-(5-octyl-2-pyrimidinyl) benzene 1- (4-heptylcyclohexyl) -4- (5-octyloxy-2-pyrimidinyl) benzene

1- (5-heptyl-2-pyridyl) -3
-(5-Octyl-2-pyrimidinyl) benzene 1- (5-heptyl-2-pyridyl) -4- (5-nonyl-2-pyrimidinyl) benzene 1- (5-heptyl-2-pyridyl) -4- ( 5-decyl-2-pyrimidinyl) benzene

5-heptyl-2- (3-fluoro-4-)
Octyloxyphenyl) pyridine 5- (4-heptyloxyphenyl) -2- (4-heptylphenyl) pyridine 5-decyl-2- (4-decanoyloxyphenyl) pyridine 4-octyloxyphenyl-4′-decyloxy Benzoate 4-octyloxyphenyl-4'-decylbenzoate 4-hexyloxyphenyl-4'-octylbenzoate

Next, the liquid crystal display device of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view schematically showing a main part of an embodiment of the liquid crystal display device of the present invention. In FIG. 1, the liquid crystal display element 1 includes a transparent electrode 3 provided on a substrate 2, an insulating layer 4 provided on the transparent electrode 3, and an alignment film 5 further provided on the insulating layer 4. A transparent electrode 7 is provided thereon, an insulating layer 8 is provided thereon, and an alignment film 9 is further provided thereon. The substrate 2 and the substrate 6 face the alignment film 5 and the alignment film 9 and face each other. The ferroelectric liquid crystal composition (hereinafter sometimes simply referred to as liquid crystal) 10 of the present invention is enclosed in the space so that a space is formed therebetween.

In the liquid crystal display element 1, the alignment films 5 and 9 have a specific tilt angle, the insulating layers 4 and 8 have a specific relative permittivity, and the liquid crystal 10 is the ferroelectric liquid crystal composition of the present invention. Other than that, it is the same as the conventionally known liquid crystal display element.

That is, as the substrate 2 and the substrate 6, a glass substrate, a transparent heat-resistant resin substrate, or the like can be used.
As the transparent electrodes 3 and 7, an ITO film, a SnO ₂ film, I
An n ₂ O ₃ film or the like can be used.

As the insulating layers 4 and 8, 5 or more,
There is no particular limitation as long as it preferably has a relative permittivity of 8 or more. For example, Ta ₂ O ₅ , Al ₂ O ₃ , H
A film formed of fO ₂ , Y ₂ O ₃ , Nd ₂ O ₃ , ZrO ₂ , TiO ₂ or the like and having a film thickness of 30 to 300 nm is preferable. Such an insulating layer is formed by a conventionally known film forming method,
For example, a vacuum evaporation method by resistance heating, a vacuum evaporation method by electron beam (EB) heating, a sputtering method,
It can be formed by an ion plating method or the like. Only one of the insulating layers 4 and 8 may be provided.

As the alignment films 5 and 9, the pretilt angle in the S _A phase of the ferroelectric liquid crystal composition of the present invention to be used (cells for a liquid crystal display device are assembled in antiparallel and liquid crystal is injected, There is no particular limitation as long as it is an alignment film having a value of 5 ° or more, preferably 8 ° or more, obtained by the crystal rotation method at the temperature indicating the S _A phase, and a rubbing-treated polyimide film, a SiO ₂ oblique vapor deposition film, or the like may be used. Can be used. Such an alignment film can be formed by a method known per se.

For example, a polyimide alignment film having the above-mentioned properties is prepared by dissolving a polyamic acid obtained from a diamine (a) and a tetracarboxylic dianhydride (b) as described below in a solvent. It can be formed by preparing a coating solution for forming, coating the coating solution on the insulating layer 4 or 8, drying, heat treatment, and then rubbing treatment.

[0136]

[Chemical 64]

[0137]

[Chemical 65]

The thickness of the polyimide alignment film is generally 5 to 20.
0 nm, particularly preferably 10 to 50 nm, and S
The film thickness of the iO ₂ obliquely vapor-deposited alignment film is generally 5 to 100 nm,
It is particularly preferably 5 to 50 nm.

The thickness (cell gap) of the liquid crystal display element 1 for enclosing the liquid crystal is generally 1 to 6 μm, preferably 1 to 2 μm, and in such a thin cell gap liquid crystal display element. In particular, the liquid crystal display device using the ferroelectric liquid crystal composition of the present invention exhibits improved high speed response.

The liquid crystal display device of the present invention may be of a segment type display system or a matrix type display system, and may be either black and white or color, and may be selected according to need. Furthermore, a color filter, a black mask, a protective layer, a heater, etc. may be provided.

[0141]

EXAMPLES The present invention will be described below with reference to examples. However, the invention is not limited by the following examples.

Example 1 Compounds shown in Table 1 and ferroelectric liquid crystal compositions having the composition ratios thereof were prepared. The compound a) represents the chiral compound (I), the compound b) represents the non-chiral compound (II), and the compounds c1) to c3) represent the non-chiral compound (III).

[0143]

[Table 1]

The ferroelectric liquid crystal composition was sandwiched between two glass plates, and the texture of the phase was observed by a polarization microscope. As a result, the phase transition temperature was confirmed as follows.

Next, this liquid crystal composition was subjected to parallel alignment treatment by applying polyimide as an alignment film and rubbing the surface of the liquid crystal composition.
It is poured into a cell of m, gradually cooled, and aligned to form a liquid crystal element.
This is sandwiched between two orthogonal polarizing plates, ± 10V, 50
When a rectangular wave of Hz was applied, the time required for the transmitted light intensity to change from 0% to 90% (response time τ) was measured. As a result, τ at 45 ° C is 63.5 μse
It was c.

The rotational viscosity coefficient (η) of this liquid crystal at 45 ° C., which was obtained from the half-value width of the polarization reversal current when a rectangular wave was applied, was 135 mPasec. Also, the spontaneous polarization P obtained from the area of the peak of the polarization reversal current when a triangular wave is applied
s was 9.8 nCcm ^-2 .

The tilt angle θ obtained by examining the movement angle (2θ) of the extinction position when a direct current of 100 V was applied and its polarity was inverted was 17.7 ° at 35 ° C.

Further, after applying a DC voltage of 10 V, the voltage was set to 0 and it was observed whether or not the alignment state upon application was maintained. It was confirmed that the same optical intensity as when the voltage was applied was obtained even when the voltage was 0, and the alignment state did not change. Therefore,
It was found that the composition of the present invention was excellent in bistability (memory property).

The ferroelectric liquid crystal composition of the present invention has a high response speed and excellent bistability. Further, as shown by the above-mentioned phase transition temperature S _A → N ^* , a uniform two-dimensional phase was confirmed by observing the S _A phase with a polarization microscope, having both S _A and N ^* phases. Therefore, it was found that the orientation was also excellent.

[Example 2] Ferroelectric liquid crystal compositions having the compounds shown in Table 2 and their composition ratios were prepared. The compound a) represents the chiral compound (I), the compound b) represents the non-chiral compound (II), and the compounds c1) to c3) represent the non-chiral compound (III).

[0151]

[Table 2]

With respect to the above ferroelectric liquid crystal composition, the phase transition temperature, the response time at 45 ° C., the rotational viscosity coefficient, the spontaneous polarization and the tilt angle were measured in the same manner as in Example 1, and the following values were obtained. Got τ = 64.1 μs, η = 134 mPas, Ps = 14.0 nCcm ⁻² , θ = 20.7 °

When bistability and orientation were evaluated in the same manner as in Example 1, both were as excellent as in Example 1.

[Example 3] Ferroelectric liquid crystal compositions having the compounds shown in Table 3 and their composition ratios were prepared. The compound a) represents a chiral compound (I), the compound b) represents a non-chiral compound (II), and the compounds c1) to c2) represent a non-chiral compound (III).

[0155]

[Table 3]

With respect to the above ferroelectric liquid crystal composition, the phase transition temperature, the response time at 45 ° C., the rotational viscosity coefficient, the spontaneous polarization and the tilt angle were measured in the same manner as in Example 1, and the following values were obtained. Got τ = 43.4 μs, η = 120 mPas, Ps = 13.0 nCcm ⁻² , θ = 17.6 ° Further, bistability and orientation were evaluated in the same manner as in Example 1, and both were the same as in Example 1. Was excellent.

[Example 4] Ferroelectric liquid crystal compositions having the compounds shown in Table 4 and their composition ratios were prepared. The compound a) represents the chiral compound (I), the compound b) represents the non-chiral compound (II), and the compounds c1) to c3) represent the non-chiral compound (III).

[0158]

[Table 4]

With respect to the above ferroelectric liquid crystal composition, the phase transition temperature, the response time at 45 ° C., the rotational viscosity coefficient, the spontaneous polarization and the tilt angle were measured in the same manner as in Example 1, and the following values were obtained. Got τ = 52.0 μs, η = 115 mPas, Ps = 8.6 nCcm ⁻² , θ = 18.1 ° Further, when bistability and orientation were evaluated in the same manner as in Example 1, both were the same as in Example 1. Was excellent.

Example 5 The compounds shown in Table 5 and the ferroelectric liquid crystal compositions having the composition ratios thereof were prepared. The compound a) represents the chiral compound (I), the compound b) represents the non-chiral compound (II), and the compounds c1) to c3) represent the non-chiral compound (III).

[0161]

[Table 5]

With respect to the above ferroelectric liquid crystal composition, the phase transition temperature, the response time at 45 ° C., the rotational viscosity coefficient, the spontaneous polarization and the tilt angle were measured in the same manner as in Example 1, and the results were as follows. Got τ = 51.0 μs, η = 136 mPas, Ps = 9.9 nCcm ⁻² , θ = 15.0 ° Further, bistability and orientation were evaluated in the same manner as in Example 1, and both were the same as in Example 1. Was excellent.

Example 6 The compounds shown in Table 6 and ferroelectric liquid crystal compositions having the composition ratios thereof were prepared. The compound a) represents the chiral compound (I), the compound b) represents the non-chiral compound (II), and the compounds c1) to c3) represent the non-chiral compound (III).

[0164]

[Table 6]

For the above ferroelectric liquid crystal composition, the phase transition temperature, the response time at 45 ° C., the rotational viscosity coefficient, the spontaneous polarization and the tilt angle were measured in the same manner as in Example 1, and the results were as follows. Got τ = 52.3 μs, η = 149 mPas, Ps = 9.0 nCcm ⁻² , θ = 14.8 ° Further, bistability and orientation were evaluated in the same manner as in Example 1, and both were the same as in Example 1. Was excellent.

Example 7 The compounds shown in Table 7 and ferroelectric liquid crystal compositions having the composition ratios thereof were prepared. The compound a) represents the chiral compound (I), the compound b) represents the non-chiral compound (II), and the compounds c1) to c3) represent the non-chiral compound (III).

[0167]

[Table 7]

With respect to the above ferroelectric liquid crystal composition, the phase transition temperature, the response time at 45 ° C., the rotational viscosity coefficient, the spontaneous polarization and the tilt angle were measured in the same manner as in Example 1, and the following values were obtained. Got τ = 53.0 μs, η = 136 mPas, Ps = 10.8 nCcm ⁻² , θ = 17.2 ° Further, when the bistability and orientation were evaluated in the same manner as in Example 1, both were the same as in Example 1. Was excellent.

Example 8 Glass substrate (thickness: 1.1 m
A transparent electrode of ITO (thickness: 150 nm) was formed on m), and an insulating layer made of Ta ₂ O ₅ (thickness: 100 nm) was formed on the transparent electrode by an electron beam vacuum deposition method. The relative permittivity of this insulating layer is obtained by pressing another copper plate on the Ta ₂ O ₅ layer formed on the copper plate and sandwiching the Ta ₂ O ₅ layer between the two copper plates, and the LCR meter. It was 22 when measured by (Yokogawa-Hewlett-Packard Co., Ltd.).

On this insulating layer, 10% by weight of N-methyl polyamic acid obtained by dehydration condensation from equimolar amounts of the diamine (a-1) and tetracarboxylic dianhydride (b-1). 20 parts by weight of pyrrolidone solution and diluent for coating solution (mixture of 20% by weight of N-methylpyrrolidone, 40% by weight of ethylene glycol monobutyl ether and 40% by weight of diethylene glycol monoethyl ether) 80
The coating liquid for alignment film obtained by mixing with 1 part by weight was applied using a spinner, and the coating film was dried at 295 ° C. for 1 hour to form a polyimide alignment film. The surface of the polyimide alignment film was rubbed with a nylon raised cloth.

Two of the substrates having the transparent electrode, the insulating layer and the alignment film obtained as described above are faced inward so that the rubbing surfaces of the alignment film are antiparallel to each other, A pre-tilt angle measuring cell having a cell gap of 3 μm was produced by bonding the same with an adhesive containing a 3 μm spacer.

The ferroelectric liquid crystal composition prepared in Example 2 was injected into this cell for measuring pretilt angle, and the S liquid crystal composition at 70 ° C.
_{When the} pretilt angle in phase _A was measured by a crystal rotation method using a polarizing microscope manufactured by Nippon Kogaku Co., Ltd., the pretilt angle was 22 °.

The two substrates, each having the transparent electrode, the insulating layer and the alignment film, obtained as described above were faced to the inside so that the rubbing surfaces of the alignment film were parallel to each other, and the rubbing directions were 2 μm. The cells were pasted together using an adhesive mixed with the above spacer to prepare a cell for a liquid crystal display element having a cell gap of 1.9 μm.

The ferroelectric liquid crystal composition prepared in Example 2 was injected into the cell for liquid crystal display device and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S = ± 42 V, τ _S = 5
˜25 μsec) was applied and the switching state was observed using a polarization microscope. Τ _S = 16 to 2
A clear switching operation with a high contrast ratio was observed in the range of 5 μsec.

Example 9 A liquid crystal display cell was prepared in the same manner as in Example 8, and the liquid crystal display cell was replaced with the ferroelectric liquid crystal composition prepared in Example 2. Injecting the ferroelectric liquid crystal composition prepared in Example,
The waveform shown in FIG. 2 is maintained at 45 ° C. (where V _S = ± 4
An electric field of 2 V, τ _S = 5 to 25 μsec) was applied, and the switching state was observed using a polarization microscope.
A clear switching operation with a high contrast ratio was observed in the range of τ _S = 11 to 16 μsec.

Example 10 A liquid crystal display cell was prepared in the same manner as in Example 8, and the liquid crystal display cell was replaced with the ferroelectric liquid crystal composition prepared in Example 2. Was injected with the ferroelectric liquid crystal composition prepared in Example 4 and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S =
An electric field of ± 42 V, τ _S = 5 to 25 μsec) was applied, and the switching state was observed using a polarization microscope. As a result, a clear switching operation with a high contrast ratio was observed in the range of τ _S = 11 to 16 μsec. ..

Example 11 A liquid crystal display element cell was prepared in the same manner as in Example 8, and the liquid crystal display element cell was replaced with the ferroelectric liquid crystal composition prepared in Example 2. Was injected with the ferroelectric liquid crystal composition prepared in Example 5 and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S =
An electric field of ± 42 V, τ _S = 5 to 25 μsec) was applied, and the switching state was observed using a polarization microscope. As a result, a clear switching operation with a high contrast ratio was observed in the range of τ _S = 11 to 16 μsec. ..

Example 12 A liquid crystal display element cell was prepared in the same manner as in Example 8, and the liquid crystal display element cell was replaced with the ferroelectric liquid crystal composition prepared in Example 2. Was injected with the ferroelectric liquid crystal composition prepared in Example 7 and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S =
An electric field of ± 42 V, τ _S = 5 to 25 μsec) was applied, and the switching state was observed using a polarization microscope. As a result, a clear switching operation with a high contrast ratio was observed in the range of τ _S = 12 to 16 μsec. ..

[Embodiment 13] In the same manner as in Embodiment 8, an ITO transparent electrode and Ta ₂ are formed on a glass substrate.
An insulating layer made of O ₅ was formed, and instead of the polyimide alignment film, SiO ₂ was obliquely deposited at a deposition angle of 83 ° on the insulating layer to form a SiO ₂ alignment film (film thickness: 25 nm). ..

The two substrates, each having the transparent electrode, the insulating layer and the alignment film obtained as described above, were faced to the inside so that the deposition directions of SiO ₂ were anti-parallel, and 3 μm. The cells were pasted together using an adhesive mixed with the above spacer to prepare a cell for pretilt angle measurement with a cell gap of 3 μm.

The ferroelectric liquid crystal composition prepared in Example 2 was injected into this cell for measuring pretilt angle, and S at 70 ° C.
_{When the} pretilt angle in phase _A was measured by the crystal rotation method using a polarizing microscope manufactured by Nippon Kogaku Co., Ltd., the pretilt angle was 9 °.

Two substrates, each having the transparent electrode, the insulating layer and the alignment film, obtained as described above were used as the alignment film.
The liquid crystal display device cells having a cell gap of 1.9 μm were produced by facing inwardly so that the vapor deposition directions of ₂ were parallel to each other and bonding them together using an adhesive containing a 2 μm spacer.

The ferroelectric liquid crystal composition prepared in Example 1 was injected into the cell for liquid crystal display device and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S = ± 42 V, τ _S = 5
˜25 μsec) was applied and the switching state was observed using a polarization microscope. Τ _S = 11 to 1
A clear switching operation with a high contrast ratio was recognized in the range of 6 μsec.

Example 14 A liquid crystal display element cell was prepared in the same manner as in Example 13, and the liquid crystal display element cell was replaced with the ferroelectric liquid crystal composition prepared in Example 2. Was injected with the ferroelectric liquid crystal composition prepared in Example 4 and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S =
An electric field of ± 42 V, τ _S = 5 to 25 μsec) was applied, and the switching state was observed using a polarization microscope. As a result, a clear switching operation with a high contrast ratio was observed in the range of τ _S = 11 to 16 μsec. ..

Example 15 A liquid crystal display cell was prepared in the same manner as in Example 13, and the liquid crystal display cell was replaced with the ferroelectric liquid crystal composition prepared in Example 2. Was injected with the ferroelectric liquid crystal composition prepared in Example 5 and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S =
An electric field of ± 42 V, τ _S = 5 to 25 μsec) was applied, and the switching state was observed using a polarization microscope. As a result, a clear switching operation with a high contrast ratio was observed in the range of τ _S = 10 to 14 μsec. ..

Example 16 A liquid crystal display cell was prepared in the same manner as in Example 13, and the liquid crystal display cell was replaced with the ferroelectric liquid crystal composition prepared in Example 2. Was injected with the ferroelectric liquid crystal composition prepared in Example 7 and kept at 45 ° C. to obtain the waveform shown in FIG. 2 (where V _S =
An electric field of ± 42 V, τ _S = 5 to 25 μsec) was applied, and the switching state was observed using a polarization microscope. As a result, a clear switching operation with a high contrast ratio was observed in the range of τ _S = 13 to 16 μsec. ..

[0187]

INDUSTRIAL APPLICABILITY The ferroelectric liquid crystal composition of the present invention, when used in a liquid crystal display device, exhibits a high-speed response, and further exhibits favorable properties in alignment and bistability. Therefore, it can be said to be a ferroelectric liquid crystal composition useful as a liquid crystal composition for a liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a main part of an embodiment of a liquid crystal display element of the present invention.

FIG. 2 shows waveforms applied to a liquid crystal display element for observing a switching state in Examples 8 to 16.

[Explanation of symbols]

 1 Liquid crystal display element 2 Substrate 3 Transparent electrode 4 Insulating layer 5 Alignment film 6 Substrate 7 Transparent electrode 8 Insulating layer 9 Alignment film 10 Ferroelectric liquid crystal composition

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazunori Kamikawa, 200, Onakazato, Fujinomiya-shi, Shizuoka, Fuji Photo Film Co., Ltd. (72) Inventor, Takahiro Ishizuka, 200, Onakazato, Fujinomiya, Shizuoka, Fuji Photo Film

Claims (2)

[Claims] 1. A liquid crystal composition comprising a chiral compound and a non-chiral compound, wherein the chiral compound has the following general formula (I): [However, A, B and C are each independently a divalent aromatic hydrocarbon group, a divalent alicyclic hydrocarbon group or a divalent heterocyclic ring which may be substituted with a halogen atom or a cyano group. represents a group, X and Y are each independently, -CH ₂ O-,
_{-OCH 2 -, - COO -,} - OCO -, - CH = CH
-Or-C≡C- is represented, R ¹ represents a linear or branched alkyl group or alkoxy group which may be substituted with a halogen atom (provided that at least one of the non-adjacent methylene groups is O, S or CO may be substituted), R ²
Represents an optionally substituted alkyl group or alkenyl group, n, p and q each independently represent 0 or 1 (provided that q = 0 when n = 0), and m represents 3 to 3. 11
Represents an integer, and * represents an asymmetric carbon atom. ] The non-chiral compound represented by the following general formula (II): [However, R ³ represents a methyl group or an ethyl group, and k
Represents an integer in the range of 3 to 16, and j is 4 to
Represents an integer in the range of 16] and a non-chiral compound represented by the following general formula (III): [Wherein D is 1,4-phenylene group or 1,4-phenylene group which may be substituted with one or two fluorine atoms or cyano group]
Represents a cyclohexylene group, E represents a 2,5-pyridinylene group, and R ⁴ and R ⁵ are each independently a straight chain having 1 to 20 carbon atoms which may be substituted with one or more fluorine atoms. Or represents a branched alkyl group (provided that one or more non-adjacent methylene groups may be replaced with O, S or CO). ] The non-chiral compound represented by these is contained, The ferroelectric liquid crystal composition characterized by the above-mentioned. 2. A liquid crystal display in which two substrates having at least a transparent electrode and an alignment film provided in this order are arranged so that the alignment films face each other, and a liquid crystal is sealed in a space between the alignment films. in the device, the liquid crystal is ferroelectric liquid crystal composition according to claim 1, the alignment film, and a pretilt angle at S _a phase of the ferroelectric liquid crystal composition 5 degrees or more, at least one 2. A liquid crystal display element, wherein an insulating layer having a relative dielectric constant of 5 or more is provided between the transparent electrode of the substrate and the alignment film.